Roadwork hassles on MacArthur Road, Route 22 in Whitehall

Q: The traffic light installed recently (and temporarily, I hope) where the ramp for traffic from Route 22 west meets MacArthur Road south has got to be malfunctioning. It stays red for MacArthur traffic for insane periods — two or three minutes sometimes. The traffic volume on MacArthur is at least 20 times that coming from 22, so the light backs up traffic on MacArthur unnecessarily. I've seen many frustrated motorists go through the red. I'm guessing (hoping) this is just temporary, but someone needs to fix the timer on that light.

— Paul Smith, Whitehall Township

Q: While driving south on MacArthur Road a few weeks ago, I noticed two new 'No Left Turn' signs in advance of construction zones. The first sign forbids left turns onto Glenside Drive at Wawa. The next prohibits lefts onto Fairmont Avenue at the Home Depot intersection. How long will left turns be forbidden at these locations? Is there a better way to keep motorists informed of significant traffic-pattern changes?

The new traffic signal that greeted motorists about a month ago at the point where the ramp from Route 22 west meets MacArthur Road south is temporary, Paul, but it will remain till nearly the end of the interchange reconstruction project, through 2013 if work remains on schedule.

The light will be replaced at some point next year by another signal that will control the flow of traffic through a "break" in the MacArthur median barrier, at a new intersection to be created there.

The existing ramp for 22 west to MacArthur south will be eliminated (at which point the temporary signal will have to go too, of course), and traffic headed in those directions will use a reconfigured version of the existing ramp from 22 west to MacArthur north: Vehicles heading south will turn left at a planned new signal, through the barrier opening, and cross over to the southbound side of MacArthur.

A similar reconfiguration will take place at the ramp-access point on the south side of 22. All 22 east traffic headed to MacArthur will use a revamped ramp that will exit the highway prior to the MacArthur bridge; the existing ramp to northbound MacArthur will be gone.

These features will eliminate the dangerous weave patterns at the merge points on 22 beneath the bridge, in both directions, that have plagued the interchange for the past 60 years, particularly in the last few decades of rising traffic speed and volume.

PennDOT's regional traffic-signals manager, Tom Walter, said the temporary light is intended to help move traffic through the difficult construction area as efficiently and safely as possible.

The signal is designed to work in concert with those immediately to the north and south, yet sheer traffic volume overwhelms the corridor at times — not a rare occurrence even before construction began.

In fact, though the temporary signal runs on various cycle lengths and timing plans during the day and week, generally MacArthur gets 22 percent more green time than the ramp during off-peak times, and 36 percent more during morning and evening rush periods, Walter said.

There is a factor that could jack up the red-phase duration, though: If the ramp from 22 backs up with traffic, sensors extend the green time to help prevent the queue from extending all the way to 22 itself — at the expense of green time for MacArthur traffic. Traffic jams on MacArthur are frustrating, but the danger factor is torqued up on 22.

Regarding the "no left turn" signs for southbound MacArthur at Glenside Road, and again at Fairmont, Dale (and Robert Eck raised the same issue), as you may have noticed, more signage has been added, especially at Fairmont, since your question pulled onto my email deck.

Left turns were prohibited at both intersections early this month when construction work eliminated the left-turn lanes at each. There was a bit of a delay from the time the initial graphic signs were posted adjacent to the traffic signals (and the left-lane signal heads were "bagged" at that time as well) and the installation of the additional placards at roadside, PennDOT officials admitted. But it was only a matter of a week or so, by my calculation.

With the upgrade, signs warning of the prohibition at Glenside are posted well in advance, at the new Lehigh Street intersection, as part of the Glenside detour of which Lehigh is a part, said PennDOT engineer John Harmonosky. "We do provide five additional signs" warning of the Glenside restriction "in reference to the detour route," he said.

At Fairmont, now that they've added extra signs, the approach is well-marked. That wasn't the case at the start, so the state fell short initially but eventually got it right. The jug-handle to the right (which turns initially toward Home Depot) serves as the detour for southbound MacArthur vehicles onto Fairmont.